Reduced graphene oxides (RG-os) have attracted considerable interest, given their potential applications in electronic and optoelectronic devices and circuits. However, very little is known regarding the chemically induced reduction method of graphene oxide (G-o) in both solution and gas phases, with the exception of the hydrazine-reducing agent, even though it is essential to use the vapour phase for the patterning of hydrophilic G-os on prepatterned substrates and in situ reduction to hydrophobic RG-os. In this paper, we report a novel reducing agent system (hydriodic acid with acetic acid (HI-AcoH)) that allows for an efficient, one-pot reduction of a solution-phased RG-o powder and vapour-phased RG-o (VRG-o) paper and thin film. The reducing agent system provided highly qualified RG-os by mass production, resulting in highly conducting RG-o HI − AcoH . moreover, VRG-o HI − AcoH paper and thin films were prepared at low temperatures (40 °C) and were found to be applicable to flexible devices. This one-pot method is expected to advance research on highly conducting graphene platelets.

In recent, highly transparent and flexible, two-dimensional (2D) graphene oxide (GO) nanosheet has been paid attention for various applications. Due to an existence of a large amount of oxygen functional groups, the single 2D GO nanosheet has an insulating, transparent, highly dispersible in the eco-friendly water, and hydrophilic property that has strong adhesion to the hydrophilic surface, which will be the best candidate for the use of an over-coating layer (OCL) and protecting layer for a conductive nanowire based indium-free transparent conductive film (TCF). The ultrathin 2D adhesive GO OCL nanosheet is expected to tightly hold silver nanowires (AgNWs), reduce sheet resistance and produce uniform TCF, providing complete solution that simultaneously solves a high haze, low transparency with a conventional OCL and mechanical instability in cases without a thick OCL. Our novel 2D insulating and hydrophilic GO OCL successfully provided a large-area, flexible, and highly transparent AgNW TCF.

wileyonlinelibrary.comactuators, [ 6 ] and absorbers of environmental pollution. [ 2,7 ] Among graphenebased materials, graphene oxides (GOs) can be described as "up-and-coming" material candidates because they are thin, light, strong, environmentally friendly, and fl exible. They also have high surface area, excellent mechanical-chemical properties, and the ability to conduct electricity within 2D nanostructures. Many research groups [ 8 ] have reported the simple preparation of rGO aerogels from GO solution by hydrothermal and freeze-drying methods or etching methods, employing a spherical template/GO composite. The microstructural features of rGO aerogels make them some of the most promising building blocks for energy-related and environmental applications. This is because these features can greatly improve working-volume deformability, can form a multidimensional conduction network, and can provide 3D interfacing or intercalation with other system components (e.g., electrolytes, reactants). [ 8 ] However, the performance and diversity of such graphene aerogel conductors are limited by the lack of a suffi cient compressive modulus (that is, they are fragile and collapse under stress). [ 4,9 ] Aerogels usually have an extremely low density due to their relatively high rigidity and/or a rather low electrical conductivity (e.g., 0.12 S m −1 with a density of 5.10 mg cm −3 ). [ 10 ] These properties can result from an incomplete reduction if mild chemical reducing conditions are employed without thermal annealing. Zhao et al. [ 11 ] reported the development of a compression-tolerant rGO sponge supercapacitor with a polypyrrole coating, which is conductive and provides mechanical reinforcement. This work showed that the use of rGO sponges in conjunction with other materials can overcome some of the shortcomings of monolithic rGO sponges. Recently, Wu et al. [ 12 ] fabricated a spongy graphene material (density = 1.15 mg cm −3 ; conductivity = 0.37 S m −1 ) that showed compressive elasticity and a near-zero Poisson's ratio by using a solvo-thermal reaction and thermal annealing. The primary remaining challenge is the synthesis of additive-free monolithic rGO aerogels that preserve the low density, high conductivity, and good elasticity inherent in GO nanosheets.In this article, we describe the development of a facile approach for fabricating support-free monolithic nitrogen (N)-doped rGO aerogels using a simple hydrothermal method employing hexamethylenetetramine (HMTA) as a stabilizerThe simple synthesis of ultralow-density (≈2.32 mg cm −3 ) 3D reduced graphene oxide (rGO) aerogels that exhibit high electrical conductivity and excellent compressibility are described herein. Aerogels are synthesized using a combined hydrothermal and thermal annealing method in which hexamethylenetetramine is employed as a reducer, nitrogen source, and graphene dispersion stabilizer. The N-binding confi gurations of rGO aerogels increase dramatically, as evidenced by the change in pyridinic-N/quaternary-N ratio. The conductivity ...

We synthesized 2-{3-[(E)-2-(dibutylamino)-1-ethenyl]-5,5-dimethyl-2-cyclohexenylidene}malononitrile as a noval nonlinear optical (NLO) chromophore for photorefractive materials. The photorefractive polymeric composite composed of photoconducting carbazole-substituted polysiloxane, NLO chromophore, and 2,4,7-trinitro-9-fluorenone exhibited excellent photorefractive properties. The gain coefficient of the composite containing 30 wt % of chromophore was as high as 390 cm -1 at the electric field of 100 V/µm, which is one of the largest values obtained so far in the field of polymeric photorefractive materials. And the composite with a thickness of 60 µm showed the maximum diffraction efficiency of 56% at 30 V/µm.

We report new step-by-step reduction methods by alternating two different reducing reagents with the order of hydrazine with NH(3) (NH)/HI in acetic acid (HI) and the reverse order (HI/NH) to understand nitrogen incorporation and removal or reduction for providing highly qualified reduced graphene oxides (rGOs).

N-doped NCO electrodes exhibited excellent electrochemical performance for supercapacitors and hydrogen evolution reaction electrocatalysis in KOH electrolyte.

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We proposed a method for measuring the magnitude of the space-charge field of the polymeric photorefractive materials. In the case of polymeric photorefractive material with low glass transition temperature, optically anisotropic chromophores are known to be reoriented under space-charge field. Simply by adding a pair of crossed polarizer units to a conventional degenerated four wave mixing setup, we could measure the birefringence of the photorefractive materials induced by a newly formed space-charge field. Since the birefringence of a given material is governed by the applied electric field, the space-charge field can be determined from the variation of birefringence using the oriented gas model.